Transmission lines route high-voltage (e.g., 2,000 volts and higher) electrical power from power plants to main or regional stations and to local substations. Distribution lines route high-voltage electrical power from substations to end users. Many such lines and supporting electrical equipment are above ground and thus may be exposed to the elements, requiring frequent inspection, repair, and/or maintenance.
Contact with any high-voltage power lines, whether above ground or below, can be lethal for workers performing such tasks. Thus, workers typically wear monitors or detectors configured to sense the proximity to high-voltage power sources and to responsively alarm or otherwise warn such workers before they reach a dangerous proximity to the high-voltage power source.
One such type of detector senses the electrical field surrounding a live high-voltage conductor, the strength and extent of such fields being proportional to the voltage level. Such detectors typically provide an audible alarm and/or a visible indication of the detected field to warn the user.